Vikings back stronger than ever in all phases on rebuilt left knee

The last four times the Bears have banged around with Adrian Peterson, they have limited him to fewer than 100 yards.

But that Adrian Peterson was not this Adrian Peterson.

The Adrian Peterson they will meet Sunday is on track for a career year with highs in average yards per game (112.8) and yards per carry (5.8).

The Vikings halfback is a candidate for NFL most valuable player and comeback player of the year at the same time as this Adrian Peterson has a rebuilt left knee after he tore his anterior cruciate and medial collateral ligaments.

The thinking was Peterson might not be ready at the start of the season, and that he would be a little off his stride until maybe 2013.

That thinking was all wrong.

Even those in the trenches with Peterson have acknowledged they are "shocked" at how quickly he has regained form.

Just three weeks ago, Peterson had told Peter King of Sports Illustrated he was "still recovering." Now, he says, "I'm 100 percent, but I'm trying to reach past that 100 percent. I've been better than I was last year the last couple weeks. I still feel I'm going to get stronger. That's what I'm excited about the most."

As strange as it seems, the knee injury may have been the best thing that could have happened to Peterson.

"It's hard for me to believe he's better than he was before the surgery, but some of the things he has done make me believe it," Vikings coach Leslie Frazier said.

Peterson said he is a better player because of the challenge his injury presented.

"It really made me look at things differently," he said. "It really made me scratch harder, dig even deeper when I was working out and training to get back. This injury is like a blessing in disguise. It helped me push through (to) another level."

Peterson said he is like one of the Dragon Ball Z warriors who transforms to a "Super Saiyan" when he needs to channel something extra.

"Some of them just fight regular, but then they come up against competition and go Super Saiyan," he said. "That's what it is. I had to go Super Saiyan to get back."

Mystical orbs and wish-granting dragons aside, there are some more, ahem, down to earth explanations for why Peterson is overcoming so many perilous obstacles.

Among them:

•He has altered his running style.

Frazier said Peterson has been less set on hitting a home run on every carry, more intent on hitting a single if the pitch isn't right for a home run.

"He still is running with power and authority," Frazier said. "He understands when to accelerate and when not to. He has cut down on negative runs. He's so patient now. He's setting up blocks so well for the offensive line."

It's not like Peterson has become contact-shy. His 567 yards after contact lead the NFL, according to STATS.

•The Vikings are using him differently.

They are having him run behind a lead blocker, usually fullback Jerome Felton, much more frequently than in the past. Earlier in Peterson's career, Vikings coaches thought he was better when he didn't run behind a lead blocker.

"We noticed in Adrian's career he did well with a lead blocker," Frazier said. "Jerome has done a terrific job for us. He has been very good for Adrian's success."

Felton has played 35 percent of the snaps this season. Last year's fullback Ryan D'Imperio, played only 15 percent.

"They are running him downhill more," an NFC pro scout said. "First he goes downhill, then he bounces. They aren't having him do as many perimeter runs."

Before this year, 21 percent of Peterson's runs went up the middle, according to STATS. This year, it's 46 percent.

•The offensive line is improved.

The addition of left tackle Matt Kalil, the fourth pick of the draft, has solidified the line. And right tackle Phil Loadholt is playing the best football of his career, according to the pro scout.

•Peterson has focused on more than his recovery.

"He's a much better pass catcher than before the injury," Frazier said. "He worked at it. He's better at pass 'pro' than ever. He has studied it."

Thus Peterson is more of a complete player.

"I tell him all the time, he's the closest I've seen to Walter Payton," said Frazier, who was Payton's Bears teammate in the 1980s. "His power, his ability to take on tacklers and make guys afraid to tackle are similar. He has world class speed, but like Walter he is a punishing runner. His toughness and elusiveness are so similar to Walter's. And to me, Walter was the best there ever was."